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782 all rights reserved near infrared (nIr) spectroscopy is a non-invasive, nondestructive, cost-effective and fast method that has a great (commercial) potential in medical technology. a growing interest in applying nIr spectroscopy in medical diagnostics, such as monitoring of skin disorders and endoscopy of the digestive system, has appeared. despite great advances in nIr technology and methodology in recent years, new innovations are needed to meet the upcoming challenges in health care.the objective of this study was to evaluate the applicability of different wavelength selection methods and to find out, whether nIr spectroscopy can be used to detect skin disorders such as sunburn, or erythema, and further, what effects erythema has on the nIr spectra of skin. this information can be used to assess the feasibility of nIr spectroscopy for skin measurements and imaging in the presence of erythema. although erythema is usually observable in the visible band, nIr spectroscopy may enhance early detection and distinguish other inflammations from erythema. Moreover, ultraviolet (uV)-induced erythema is a convenient and controlled way to cause an inflammation, and because nIr spectra are related to the dermal biochemistry, nIr spectroscopy could be used, for example, for on-line monitoring of drug treatments.nIr radiation can penetrate cutaneous tissue, as well as other biological materials, for several millimeters. Hence nIr can detect phenomena that occur in the deeper layers of skin, for example, erythema-related water influx, thickening of the stratum corneum and metabolic changes. usually, however, most of the information of nIr measurement originates from department of electrical engineering and automation, university of Vaasa, faculty on technology, po Box 700, fI-65101 Vaasa, finlandThe acute effects of sun-bathing on the near-infrared absorption spectra of human skin were studied by exposing the shoulders of a male test subject to bright Finnish high summer mid-day sun. The spectra were measured before, immediately after and for several days after exposure. Four different spectral processing and classification methods were applied to the data set to identify differences caused by exposure to the sun. The spectrophotometer and measuring procedure were found to cause some systematic errors, calling for further development, even though they could, to a large extent, be compensated for computationally. Spectral regions indicating ultraviolet radiation-induced erythema were located and the degree of erythema could be predicted correctly but the signal is weak. This paper discusses promising wavelength selection methods to study the dermal effects of exposure to the sun, as well as difficulties and remedies of near infrared spectroscopic measurements of the skin.

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or map the set of feasible motions onto a network of In this paper, a hierarchical A* -based method for motion planning of robot manipulators is presented. The algorithm's advantage is its simplicity. The algorithm is also shown to be resolution complete.The algorithm searches the robot's configuration space with many different "step sizes" at the same time. The step size denotes the distance between the nodes A' expands during the search. When a path candidate goes far from the obstacles, a big step size is used. When it goes near the obstacle surfaces, a smaller step size is used.Two simulated robot workcells are provided for experimental study. The motion planning of 5 and 6-degrees-of-freedom industrial robots appears to be reasonably fast. P IntroductionThis paper studies a point-to-point path planning problem for robot manipulators. Currently the most effective path planners utilize hierarchy in searching. They can be roughly categorized cell decompositions and roadmap or skeleton methods [11] and [8].Cell decomposition approaches are based on decomposing (either exactly or approximateiy) the set of free configurations into simple non-overlapping regions called cells, see e.g. [2], [9], [ll], [3] and [l]. The adjacency of these cells is represented in a connectivity graph that is searched for a path. If a cell is not free then it is subdivided into some smaller cells. If they are not free then the subdivision process is further continued hierarchically.Cell decomposition approaches use sophisticated algorithms for constructing adjacent free cells. To check whether a cell is free needs to model swept volumes of the manipulator links [ I l l or to calculate distances between the robot and the obstacles [6], 181. Roadmap or skeleton approaches attempt to retract one-dimensional lines, called the roadmap, skeleton, or subgoal network, see e.g. [4], [ll], [8], [lo]. The nodes of the roadmap graph or subgoals are generated by heuristic rules guiding the intelligent sampling of the search space. The subgoal generation can be done by preprocessing the search space or on-line, during the path planning. This stage can be called global planning. Local planning refers to finding a collision free path from one subgoal to another.In skeleton approaches, the local planner usually do not know how difficult it is to find a path from one subgoal to another. Therefore it has to decide on when to stop searching and to choose another subgoal. In other words, the path planners have to allocate the computational resources between the global and the local planners well to be effective. This may need sophisticated algorithms.The points mentioned above do not claim that these path planners are not effective. However, they may have quite complicated algorithmic structures.In this paper, we propose a simple path planning algorithm that take into account hierarchy in search. However, it avoids solving the complicated cell decomposition problem. It uses onedimensional lines as the roadmap methods do. On the other hand, it does not gen...